There has also been a CBS radio news report that I heard that this spreadsheet contained counts of media coverage. CBS News notes how Lanza was in competition with the Norway killer for the amount of attention that he received:

Sources say Lanza saw himself as being in direct competition with Anders Breivik, a Norwegian man who killed 77 people in July 2011. . . .

Two officials who have been briefed on the Newtown, Conn., investigation say Lanza wanted to top Breivik's death toll and targeted nearby Sandy Hook Elementary School because it was the "easiest target" with the "largest cluster of people." . . .

Also, I suspect that Lanza chose an elementary school so he could - in his mind - "score the most points" by claiming the most victims and also get victims who would generate the most sympathy. Other killers have also compared themselves to those in past attacks and hoped to beat their numbers. From the WSJ:

Never publish a shooter's propaganda. Aside from the act itself, there is no greater aim for the mass killer than to see his own grievances broadcast far and wide. Many shooters directly cite the words of prior killers as inspiration. In 2007, the forensic psychiatrist Michael Welner told "Good Morning America" that the Virginia Tech shooter's self-photos and videotaped ramblings were a "PR tape" that was a "social catastrophe" for NBC News to have aired.

Hide their names and faces. With the possible exception of an at-large shooter, concealing their identities will remove much of the motivation for infamy.

Don't report on biography or speculate on motive. While most shooters have had difficult life events, they were rarely severe, and perpetrators are adept at grossly magnifying injustices they have suffered. Even talking about motive may encourage the perception that these acts can be justified.

Police and the media also can contain the contagion of mass shootings by withholding or embargoing details:

Minimize specifics and gory details. Shooters are motivated by infamy for their actions as much as by infamy for themselves. Details of the event also help other troubled minds turn abstract frustrations into concrete fantasies. There should be no play-by-play and no descriptions of the shooter's clothes, words, mannerisms or weaponry.

No photos or videos of the event. Images, like the security camera photos of the armed Columbine shooters, can become iconic and even go viral. Just this year, the FBI foolishly released images of the Navy Yard shooter in action.

Finally, journalists and public figures must remove the dark aura of mystery shrouding mass killings and create a new script about them.

Talk about the victims but minimize images of grieving families. Reports should shift attention away from the shooters without magnifying the horrified reactions that perpetrators hope to achieve.

Decrease the saturation. Return the smaller shootings to the realm of local coverage and decrease the amount of reporting on the rest. Unsettling as it sounds, treating these acts as more ordinary crimes could actually make them less ordinary.

Tell a different story. There is a damping effect on suicide from reports about people who considered it but found help instead. Some enterprising reporters might find similar stories to tell about would-be mass shooters who reconsidered.

Rampage shootings are fed by many other sources that also must be addressed, of course. Many shooters have suffered bullying, which inflicts a sense of powerlessness that their actions aim to overcome. Some (though not most) shooters have had prior contact with mental health services, and many give recognizable warnings beforehand to friends, family or teachers. Institutionally and individually, we must learn to take these signs seriously and report them to authorities. Massacres also would not be nearly so lethal without the widespread availability of guns and high-capacity magazines designed more for offense than for defense.

But, guns aside, these factors are more or less perennial problems of human life and cannot, alone, bear the blame for rampage shootings. In coverage of these events, the focus on insanity particularly risks playing into the need of potential future shooters to convince themselves that the world rejects them, rather than the other way around. The minority who really are psychotic, or just act impulsively, are even more likely to draw their ideas from the cultural ether. . . .